Affiliation: Multidisciplinary Neuroprotection Laboratories, Duke University Medical Center, Durham, North Carolina, United States of America; Department of Anesthesiology, Duke University Medical Center, Durham, North Carolina, United States of America.

Mentions:
To determine progesterone’s role in cytokine production, 4 h of LPS (30 ng/ml) exposure was used to stimulate BV-2 cell cytokine production in the presence of escalating doses of progesterone. Pretreatment of progesterone dose-dependently attenuated LPS-induced soluble TNF-α (sTNF-α) production in the supernatant. Significant sTNF-α decrease (approximately 20%) occurred with 10−7 and 10−6 M progesterone (Figure 2A). In time course experiments, as the precursor of sTNF-α, transmembrane TNF-α (mTNF-α) expression on BV-2 cells was found to increase at 1 h, reached maximum at 4 h, and then gradually decreased to 1-h levels by 24 h after LPS addition (Figure 2B). Progesterone also reduced LPS-induced mTNF-α expression in a dose dependent manner with similar maximal reduction at both 10−7 and 10−6 M (Figure 2C). Since 10−7 M is within the physiological concentration range of progesterone in blood in the female mouse [37], it was used for further experiments. Finally, mifepristone, a progesterone receptor antagonist, reversed progesterone’s effect on mTNF-α expression starting at 10−9 M (Figure 2D, 2E).

Mentions:
To determine progesterone’s role in cytokine production, 4 h of LPS (30 ng/ml) exposure was used to stimulate BV-2 cell cytokine production in the presence of escalating doses of progesterone. Pretreatment of progesterone dose-dependently attenuated LPS-induced soluble TNF-α (sTNF-α) production in the supernatant. Significant sTNF-α decrease (approximately 20%) occurred with 10−7 and 10−6 M progesterone (Figure 2A). In time course experiments, as the precursor of sTNF-α, transmembrane TNF-α (mTNF-α) expression on BV-2 cells was found to increase at 1 h, reached maximum at 4 h, and then gradually decreased to 1-h levels by 24 h after LPS addition (Figure 2B). Progesterone also reduced LPS-induced mTNF-α expression in a dose dependent manner with similar maximal reduction at both 10−7 and 10−6 M (Figure 2C). Since 10−7 M is within the physiological concentration range of progesterone in blood in the female mouse [37], it was used for further experiments. Finally, mifepristone, a progesterone receptor antagonist, reversed progesterone’s effect on mTNF-α expression starting at 10−9 M (Figure 2D, 2E).

Affiliation:
Multidisciplinary Neuroprotection Laboratories, Duke University Medical Center, Durham, North Carolina, United States of America; Department of Anesthesiology, Duke University Medical Center, Durham, North Carolina, United States of America.